Harnessing the power of EPOC for faster fat loss

As we all know, fatloss requires a calorie deficit to be created, burn more calories than you consume and you lose weight. Maintain adequate protein and fat intakes to ensure muscle mass isn’t lost and you regulate the hormonal activity optimally, and drop the carbs to necessary levels (since its usually an excess of carbs that has added the body fat you’re trying to get rid of…just don’t go too crazy with the cut!)

So if diet is the overriding factor when it comes to fat loss, how can you speed the process along?

By tapping in to an effect known as EPOC – Exercise Post-Oxygen Consumption, sometimes referred to as afterburn.

This effect is what happens to your body after higher intensity exercise, the higher the intensity, the longer the effects of afterburn last.

Depending on the type of exercise done and the intensity of that exercise, the level of the oxygen debt to be paid back will vary. Low level cardio such as walking, jogging, cycling (at a leisurely pace), group exercise classes create a relatively low level of oxygen demand and little in the way of muscular demands. Therefore, shortly after the exercise finishes, breathing returns to normal (assuming your fitness level is in any way reasonable…) and your body returns to burning the same number of calories as before.

At the start of exercise, regardless of intensity, there is a moment of higher energy production than your standard amount, as exercise continues, you require more oxygen to help with energy demands and your breathing rate climbs to provide it.

Your exercise intensity will fall over time as your endurance energy systems are slower and can’t maintain higher energy outputs, but there is still the initial oxygen deficit to “pay back.”

o2 debt

With higher intensity exercise such as lifting heavy things off the floor and putting them down again, sprinting, high intensity body weight circuits etc create a much bigger oxygen debt, as well as muscular damage

When you do intense exercise, you overload your muscles, helping stimulate protein turnover, protein building, and an increase (or at least maintenance) of muscle mass.

In the post exercise period, oxygen consumption (and therefore calorie burn) is elevated.

After an intense workout, it’s necessary for the body to metabolise additional fuel, replenish energy stores, and reload the depleted oxygen stores. Further, oxygen consumption (and remember from above that oxygen consumption is related to energy use) is boosted due to:

– Higher body temperature

– Increased activity of the cardiovascular system

– Higher levels of hormones that increase metabolic activity

– Energy pathways and the conversion of things like lactate into glucose (for energy replenishment)  or amino acids (for protein       synthesis)

– Recovery of muscle damage

So, with intense exercise, more oxygen is being consumed (and energy being used) during the exercise, after the exercise, and pretty much all day long. In fact, depending on the intensity of the exercise, the afterburn effect has been shown to last up to 36 hour after exercise! And interestingly, there is a higher level of fat burn post exercise too.

During high intensity exercise, the rate of fat breakdown is high. However, fatty acid entry into the bloodstream is limited, but on finishing your exercise, this limitation subsides and the fats enter circulation for transport to be used as fuel during recovery.

So, how can you start using this effect in your training?

1. Use full body exercises such as deadlift, squat, bench press variations done for sets of 5 to 12 reps with loads suitable for the rep ranges chosen.

2. Keep your rest times appropriate. sets of 4-6 get 90 – 120s, 8-12 reps get about 1 minute. For fat loss your next set should be started with slightly higher heart rate and your breathing should still be slightly elevated.

3. Higher intensity circuits as your conditioning of choice, or as shorter standalone workouts.

Here is a great way to build a conditioning circuit to help switch on the afterburn effect:

Pick an exercise from each of the lists, put them together with the time options below and voila! great conditioning, increased work capacity (fitness) and boosted fat burn for hours after the workout ends!

Exercise A Exercise B Exercise C Cardio
 Pushup  KB swing  Roll outs  Sprint (treadmill or outdoors)
 Hindu pushup  Goblet squat  Leg lowers  Bike
 Reverse hindu  Frog squat  Reverse crunch  Rower
 DB press  Bodyweight squat  TRX pike  Skipping
 DB shoulder press  Reverse lunge  Plank

So for example, 20 seconds of hindu pushup, 10 sec transition to KB swings for 20 sec, 10 sec transition to reverse crunches for 20 sec and a final 110 sec transition to 60 sec treadmill run. Rest 60-90 seconds, then repeat for a total of 3 rounds, lie on the floor and try not to die…

If you find the 20/10 work to rest split to challenging to begin with, this can be dropped to 15/15 or even 10/20 before you start to build up again. Equally the cardio component can be as low as 30 secs and built up over time to a max of around 90 seconds.

Total time for 30 sec cardio rounds would be around 10 mins (with 90s recovery between rounds) and up to 12 mins for 90 sec cardio segments and 60s rest time.

Have fun, stay strong


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